In today's portable electronic devices, there are typically one or more radio frequency (RF) modules that serve to provide wireless data exchange between the device and its operating environment. Such an RF module requires one or more antennas to transmit/receive data signals. The RF module and antennas are mounted in some manner on a printed circuit board (PCB).
Until recently, the one or more antennas have been designed independently as a printed shape on the (PCB) or as an individual component to be assembled near an RF integrated circuit (RFIC) die. However, the assembly of the individual antenna or antennas on the board is problematic in the context of mass production.
Recently, it has become popular to integrate the one or more antennas into the RF module. It is understandable that the integration of the one or more antennas into the module brings a huge advantage in terms of cost and performance. However, cooling becomes very challenging since cooling devices used to transfer heat away from the RF module, such as heat sinks and heat spreaders, should be mounted so as not to electromagnetically interfere with the signal transmission/reception of the one or more antennas.
To address this interference problem, cavity-down type integrated circuit packages have been proposed. In such a package, the antenna-embedded package has a cavity formed on its bottom surface in which the RFIC die is mounted. This cavity-down type integrated circuit package is mounted on a top surface of the PCB with a heat sink or heat spreader mounted below the PCB. This way, the heat sink or heat spreader does not electromagnetically interfere with the signal transmission/reception of the one or more antennas. However, there must be some type of heat transfer mechanism/medium employed between the components to effectively transfer heat away from the RFIC die.